The invention relates to a distributed energy grid connection and reactive compensation composite control method, which comprises the following processes of obtaining real-time grid voltage VS, system current IS and DC bus voltage Vdc through a collection module and then transmitting the real-time grid voltage VS, the system current IS and the DC bus voltage Vdc to a digital signal processor DSP; and obtaining reactive current and grid-connected current in a load through calculation, comparing the reactive current and the grid-connected current with a set adjustment target value, generating a fixed-frequency PWM pulse through a PI controller to drive an inverter power tube IGBT to be turned on and turned off, controlling output of each phase of grid-connected current and compensation current of a system, and outputting the maximum grid-connected power by the system in an active priority mode, firstly compensating the reactive current of the system in a regional reactive priority mode and providing the system with active compensation and reactive compensation in a regional balance mode. Through controlling output of each phase of grid-connected current and compensation current of the system, a distributed energy access device can be more intelligently used for a regional power grid and has the characteristic of high grid-connection efficiency.